1. Field of the Invention
The present invention relates to privacy masking for video camera images and, more particularly, to a privacy mask which is transformed to account for changes in the field of view of the camera.
2. Description of the Related Art
Video surveillance camera systems are found in many locations and may include either fixed cameras that have a fixed field of view and/or adjustable cameras that can pan, tilt and/or zoom to adjust the field of view of the camera. The video output of such cameras is typically communicated to a central location where it is displayed on one of several display screens and where security personnel may monitor the display screens for suspicious activity.
When employing a video surveillance camera system, the area within the field of view of a camera in the system may include both the area for which monitoring is intended and private areas. In such circumstances, it is known to provide privacy masking which obscures that portion of the video image which corresponds to the private area. When the camera is a pan, tilt, zoom camera having an adjustable field of view, the portion of the displayed image corresponding to the private area will change as the field of view of the camera changes. Although various systems have addressed the need to provide privacy masks in a surveillance camera system, there remains a need to improve the performance of such systems.